1. Field of the Invention
The present invention relates to a cartridge mountable into and demountable from the body of an image-forming apparatus.
2. Description of the Related Art
It is known that some image-forming apparatuses, such as laser printers, include cartridges that are demountably mounted in the bodies thereof (see Japanese Unexamined Patent Application Publication No. 2007-79139, for example).
Such cartridges house rotatable members such as a photoconductor drum on which an electrostatic latent image is to be formed and a development roller that supplies toner onto the peripheral surface of the photoconductor drum. In a case of a development cartridge, a rotatable member is positioned with part of the peripheral surface thereof exposed from the casing of the development cartridge. The cartridge is mounted in an apparatus body such that the part of the peripheral surface of the rotatable member exposed from the casing is positioned on the rear side in the apparatus body.
Such a cartridge has on one side thereof a gear cover. The gear cover has an insertion hole. In a state where the cartridge is mounted in the apparatus body, the tip of the input gear significantly protrudes from the insertion hole of the gear cover, whereby the input gear is connected to a driving gear provided in the apparatus body. Thus, a driving force for driving the rotatable member, such as a photoconductor drum or a development roller, is input from the driving gear to the input gear.
Specifically, a guide wall that guides the cartridge is provided in the apparatus body. The guide wall is angled such that the rear side thereof is near the cartridge. The guide wall has a through-hole at a position thereof facing the driving gear.
The cartridge is provided with a coil spring that urges the input gear toward the outside in the axial direction of the rotatable member. The input gear constantly receives the urging force of the coil spring. Therefore, the tip of the input gear significantly protrudes from the insertion hole of the gear cover.
When the cartridge starts to be mounted into the apparatus body, the tip of the input gear comes into contact with the guide wall. When the cartridge is further moved into the apparatus body, the guide wall narrows, and as the cartridge is guided by the angled guide wall, the input gear retracts into the cartridge. When the mounting of the cartridge into the apparatus body is completed, the input gear faces the through-hole of the guide wall. Then, the input gear receiving the urging force of the coil spring moves outward in the axial direction, passes the through-hole and the insertion hole, and protrudes toward the driving gear. Consequently, the input gear is connected to the driving gear.